Saturn Apollo Program

This view depicts engineers conducting a system test on the Saturn V instrument unit (IU) at International Business Machines (IBM) in Huntsville, Alabama. IBM is a prime contractor for development and fabrication of the IU. The IU is vital to the proper flight of the vehicle. It contains navigation, guidance, control, and sequencing equipment for the launch vehicle. Three-feet tall, twenty-one feet in diameter, and weighing about 4,000 pounds, the IU is mounted atop the S-IVB (third) stage, between the S-IVB stage and the Apollo spacecraft.